Dimethylol urea acetal condensation product and process of producing the same



Puma 'Jan.1 6,1 940 i UNITED STATES PATENT OFFICE:

. DIMETHYLOL UREA ACETAL CONDENSA- TION PRODUCT AND PROCESS (BF EB- DUCING THE SAME Theodore S. Hodglns, Royal Oak, and Almon G.

Hovey, Pleasant Ridge, Mich assignors to Reichhold Chemicals, Inc., formerly Beck,

Koller & Company, Inc., Detroit, Mich.

No Drawing. Application November 10, 1938, Serial No. 239,878

6 Claims. (01. 260-70) The invention relates to the preparation of The production of the dimethylol urea may be resinous condensation products suitable for use represented generally by the following equation:

as coating compositions, said condensation prod- (Treat-formaldehyde dimethyloi urea ucts being formed by reacting an acetal with di- NHCHOH methylol urea, the term acetal being construed 20H 0 6 broadly as including hemi-acetals and formals. f

The present application is a continuation-in- (alkaline catalyst) NHCHsOH part of our prior application Serial No. 203,149 The preparation the Metal y be p filed April 20, 1938. Sented as follows: l According to our process two definite starting R 10 materials are employed, namely an acetal and XQEQ+QRIQQ dimethylol urea. By using definite starting ma- ORH+H O terials substantial uniformity of product may be and 1/01.

insured, and results obtained with one batch may 15 be reproduced again and again, which is of importance from the commercial standpoint. Furthermore, according to our process it is possible OE to operate under substantially anhydrous condifor the hemi-acetal, where It represents an aryl tions owing to the relatively small quantity 01 or alkyl group and either E3 or R represents an water to be eliminated. Our process also elimiaryl or alkyl group or hydrogen While the other hates to a large extent the problem of recoverrepresents. an aryl or aliayl group.

ing the solvent from azeotropic mixtures. In order to indicate scope oi The dimethylol urea may be prepared accordandthe type of 'acctals usable cennec ing to known methods, one method being dethe process, the tcllowing tables of scribed by Elnhorn and Hamberger, Ber., 41, 24 given in order of their empirical formulae and (1908). Other methods of preparation may be classification to the length at the aldehyde employed if desired. chain:

Aom'nzs Fania so ac Bolling 8 do point gar? "E(OG;H a es oanm c (Jake oniiznzcnm was vistas. W

CHKOIJH: CHs.CH:CH|)t 176-7 cnuoontcntcntoncs -c1.s 180-1 CHQO.CE2.CH(CE2):2S mes 0.825@20O. CH|O.CHi.CHs.CH{vH:}2I'J ms 0.sss@2n0. on, O.CH:.CH(CH$).GH3.CK:}Q 205 CHflOCl uh zoo ammo" o. 40 40 0.03: 9...... 0:15:01 0H. l 74-75 Lemon 0.

0 In a I 0cm m.......-.. 001:0. 03k 1 onon ocrnomon 550 1L...-..... OHIOI 03k O H.

12... who m0 OH.EC-OHi sir-c 19a as l3... 01431.04

TABLE II AOIPIALS Fnou Aca'rsmrmn m Bram Awn- Mel Bolling Specific at $1 31? pon pom: mm

- '0. '0. OH OH.CH(O.CH|)| 04.4 osmoo'o i4 5 1: cnlomomoolm -00 16 o.H o, omomoomm 102.2 0.821 22% 17 n CH;.CH(O.C;H1)1 146.8 0.826 are is Cu nO: cmonlocmcmoflolh 168-170 o.sm@22o 19 (312 1101 I-OHI I i).CHQ-OHIII 117-9 Q32552l C.

no 0 11.0, omomoomcmomomhl: 210.8 0.8347615 o.

0.011: 21. 0111-01 OHLCQ s15 1.000200'0.

0. HI Q-CHK m. 0ain0| onto OHOH 0.0K! -7 uicaia'o. O.CH.CH10H 28 05 CH|.C

24. C|Hu04 H1O CHJIC CH1 94.5-6 an ocnwmyo ocmomyo 0.011. as 0111 0, (CHmCILO 122-3 0.0641@00.

0.0H{\ as 01111.0. (cHmOEcmc CHOH 2244; mmao o. 0.03.0111011 OIHIIOI mmacaomo The acetals given in the tables may be prepared according to the methods given in Bellstein, vols. 1 and 19, and are adapted to be combined with dimethylol urea according to the processes herein outlined. However, we are not concerned with the particular methods of preparing the like.

These resinous condensation products are useful as coating compositions, and compatible with the commonly used paint and varnish solvents and with most types of commercial alkyd resins and nitrocellulose, etc.

A resin produced in accordance with our invention has extreme hardness and toughness when baked 1 hour at 250-300 F. It is very useful as a fortifying resin to be added to alkyd resins both in clear and pigmented films to improve hardness and toughness.

As illustrative of the invention the following examples are iven:

Example 1 1 mol of dimethylol urea. parts by weight) is added to 1 mol (ISO-parts) of normal butyl formal in the presence of an excess of commercial xylol (200 parts by weight) and of an acid catalyst, such as ortho phosphoric acid, in sumcient quantity to bring the pH value of the reaction mixture within the range of 5.5-6.5. The progress of the reaction, which is carried on at boiling, of the system is followed by the elimination of water. The end point is determined when approximately 1 mol of water is eliminated. About two hours are required to form a slight viscous solution of a water-white heat-hardening resin which possesses stability on storage. The resulting resin solution can be thinned with alco hols, aromatic hydrocarbons and to a limited extent with straight chain hydrocarbons. The product is useful as an ingredient of various rapid baking hard synthetic enamels particularly in combination with alkyd resins.

Example 2 Parts by weight 1 mol dimethylol urea 120 1 mol n-butyl formal 180 Phosphoric acid 2.8

These materials are refluxed for 2 hours at boiling and vacuum distilled in the presence of butyl alcohol to the desired viscosity. The resulting water-white resin is diluted with butyl alcohol or mixtures of butyl alcohol and xylol or other solvent to the desired solids content.

Example 3 1 mol of dimethylol urea is added to 2 mols of n-butyl formal in the presence of an excess of dioxane, and of suflicient hydrochloric acid Example 4 1 mol of dimethylol urea is added to 1 mol of n-octyl formal in the presence of an acid catalyst and of an excess of the monoethyl ether of ethylene glycol as a flux. The reaction may be carried out as in Example 1, or Example 2, the product being similar in its characteristics but, of greater flexibility owing to the increased carbon length of the formal employed.

Example 5 1 mol of dimethylol urea is added to 2 mols of n-octyl formal in the presence of a suitable flux and of an acid catalyst, and the reaction carried out as outlined in Example 1 or Example 2. The resulting product is softer and more flexible than is obtained where only 1 mol of the formal is employed per mol of dimethylol urea.

Example 6 (a) To 1 mol of dimethylol urea (120 grams), 200 grams of a flux as butanol, and 1 mol n-butyl acetal was added. The acidity of the system was The sysoff the water of reaction along with the solvent.

.The progress of the reaction is noted by the elimination of water during the distillation. After 4-5 hours a slightly viscous water-white resinous product was obtained which was soluble in alcohol. aromatic hydrocarbons and to a limited extent in straight chain hydrocarbons.

Similar resins are prepared from n-butyl acetal and dimethylol urea in accordance with the pro- I cedure outlined above, in the presence of other monohydric alcohols or of fluxes such as dioxane, 'propyl n-amyl ket'one, xylene, toluene and the like.

' (b) A resin was prepared in accordance with the procedure outlined under (a) above but using 2 mols of n-butyl acetal per mol of dimethylolurea in the presence of a' fiux.

The resulting product possessed greater softness and flexibility indicating that part of the second group had reacted.

Example 7 Resins were prepared according to the processes outlined in Example 6 (a) and (b) but using n-octyl acetal. Here the products were not as hard as in the previous cases, but possessed excellent solubility in straight chain hydrocarbons, such as mineral spirits, and in the usual varnish oils such as linseed oil, tung oil and fish oils. Various fluxes were used without materially affecting the resulting product. Where 2 mols of the acetal were used per mol of dimethylol urea the resulting product had greater flexibility than when only 1 mol of the acetal was employed.

Example 8 (a) To 1 mol of dimethylol urea (120 grams) 200 grams of a flux (dioxane) and 1 mol (159 grams) cyclonol (methyl cyclohexanone glycerol acetal) were added. The mixture was then treated as described in Example 6 (a) and a product generally similar to that obtained under 6 (a) was obtained. Like results were obtained when operating in the presence of monohydric alcohols or other fluxes.

(b) A resin was prepared as in 8 (a) but using 2 mols of cyclonol per'mol of dimethylol urea.v

The product had a greater flexibility than that obtained under 8 (a) GENERAL NOTES in hydrocarbons than that obtained from n-butyl Also the product. obtained from n-butyl acetal is softer and has slightly greater solubility formal, and similarly the product obtained from n-octyl acetal is softer, and more flexible than that obtained from n-c'ctyl formal.

3. Thereaction mixture should be maintained at a pH of 5.5-6.5 by the use of a suitable acid catalyst such as phosphoric acid, hydrochloric acid or sulphuric acid.

4. Various types of fluxes such as the monohydric alcohols, the ketones, the aromatic hydrocarbons and the ethers may be employed in connection with the process, and good results 'areobtained with all of these types of flux.

5. In general the product obtained by the presout process' is water-white, heat-hardening and possesses great stability on storage. It is soluble in alcohols, aromatic hydrocarbons, and to a greater or less extent in straight chain hydrocarbons depending on the number of C atoms in the acetal employed in the reaction.

' constituting the principal reacting ingredients.

3. A process of producing an artificial resin which comprises reactingpreformed dimethylol urea and a preformed acetal while maintaining a pH of 5.5-6.5 in the presence of a flux, .the dimethylol urea and acetal constituting the principal reacting ingredients.

4. A clear waterwhite, heat-convertible resin formed by reacting preformed dimethylol urea and a preformed acetal, the acetal and dimethylol urea constituting the principal reacting ingredients, said resin being particularly adapted for use as an ingredient in coating compositions, and being compatible with the commonly used paint and varnish solvents and with commercial alkyd resins and nitrocellulose, and having extreme hardness and toughness when baked for 1 hour at 250-300 F.

5. A coating composition comprising the resin defined in claim 4 and a non-aqueous solvent.

6. A coating composition comprising the resin defined in claim 4 and a common varnish solvent.

THEODORE s. HODGINS.

ALMON G. HOVEY. 

